Torque converter including damper assembly with hysteresis control package

Abstract

A torque converter is provided. The torque converter includes an axially movable turbine piston and a damper assembly fixed to the turbine piston. The damper assembly includes a first cover plate, a second cover plate, a plurality of fasteners fixing the first cover plate and the second cover plate together such that the second cover plate is spaced from the first cover plate, a first drive flange axially between the first and second cover plates, a second drive flange axially between the first and second cover plates and an elastic element axially between the first and second cover plates. The first cover plate, the second cover plate, the second flange, the fasteners and the elastic element are axially movable with the piston turbine independently of the drive flange. The elastic element is configured to create a controlled rotational hysteresis between the second drive flange and the first and second cover plates during the axial movement of the first cover plate, the second cover plate, the second flange, the fasteners and the elastic element. A method of forming a torque converter is also provided.

What is claimed is: 
     
       1. A torque converter comprising:
 an axially movable turbine piston; and 
 a damper assembly fixed to the turbine piston, the damper assembly including:
 a first cover plate, 
 a second cover plate, 
 a plurality of fasteners fixing the first cover plate and the second cover plate together such that the second cover plate is spaced from the first cover plate, 
 a first drive flange axially between the first and second cover plates, 
 a second drive flange axially between the first and second cover plates, and 
 an elastic element axially between the first and second cover plates, the first cover plate, the second cover plate, the second drive flange, the fasteners and the elastic element being axially movable with the turbine piston independently of the first drive flange, the elastic element configured to create a controlled rotational hysteresis between the second drive flange and the first and second cover plates during the axial movement of the first cover plate, the second cover plate, the second drive flange, the fasteners and the elastic element. 
 
 
     
     
       2. The torque converter as recited in  claim 1  wherein the elastic element is diaphragm spring mounted on the fasteners. 
     
     
       3. The torque converter as recited in  claim 2  wherein the diaphragm spring, at an inner circumferential surface thereof, includes radially outwardly extending notches each configured for receiving one of the fasteners. 
     
     
       4. The torque converter as recited in  claim 1  wherein the first drive flange is an inner drive flange including a drive hub configured for connecting to a transmission input shaft and the second drive flange is an outer drive flange having an inner circumference that is radially outside of an inner circumference of the drive hub. 
     
     
       5. The torque converter as recited in  claim 1  wherein each of the fasteners includes a first shoulder for contacting the first cover plate, a second shoulder for contacting the second cover plate and a third shoulder for contacting the elastic element. 
     
     
       6. The torque converter as recited in  claim 5  wherein the fasteners are sheet metal rivets. 
     
     
       7. The torque converter as recited in  claim 1  wherein the elastic element is axially preloaded between surfaces of the fasteners and a surface of the second drive flange. 
     
     
       8. The torque converter as recited in  claim 1  wherein the elastic element is axially between the first drive flange and the second drive flange. 
     
     
       9. The torque converter as recited in  claim 1  wherein the elastic element forces the second drive flange away from the first drive flange and toward the second cover plate. 
     
     
       10. The torque converter as recited in  claim 1  wherein the elastic element is spaced away from the first drive flange by the fasteners. 
     
     
       11. The torque converter as recited in  claim 1  wherein the damper assembly includes springs, the first and second cover plate configured for driving the first and second drive flanges via the springs, the elastic element being radially outside of the springs. 
     
     
       12. The torque converter as recited in  claim 1  wherein the fasteners extend through slots formed in the first drive flange and slots formed in the second drive flange. 
     
     
       13. The torque converter as recited in  claim 1  wherein the fasteners extend through holes formed in the first cover plate and holes formed in the second cover plate. 
     
     
       14. A method of forming a torque converter comprising:
 fixing a first cover plate to a turbine piston; and 
 providing a first drive flange, a second drive flange and an elastic element axially between the first cover plate and a second cover plate and fixing the first and second cover plates together by fasteners to form a damper assembly such that the first cover plate, the second cover plate, the second drive flange, the fasteners and the elastic element are axially movable with the turbine piston independently of the first drive flange and the elastic element is configured to create a controlled rotational hysteresis between the second drive flange and the first and second cover plates during the axial movement of the first cover plate, the second cover plate, the second drive flange, the fasteners and the elastic element. 
 
     
     
       15. The method as recited in  claim 14  wherein the fixing the first and second cover plates together includes mounting the elastic element on the fasteners. 
     
     
       16. The method as recited in  claim 15  further comprising forming the elastic element as a diaphragm spring including, at an inner circumferential surface thereof, radially outwardly extending notches each configured for receiving one of the fasteners. 
     
     
       17. The method as recited in  claim 14  wherein the first drive flange is an inner drive flange including a drive hub configured for connecting to a transmission input shaft and the second drive flange is an outer drive flange having an inner circumference that is radially outside of an inner circumference of the drive hub. 
     
     
       18. The method as recited in  claim 14  wherein the fixing the first and second cover plates together includes contacting the first cover plate with first shoulders of each of the fasteners, contacting the second cover plate with second shoulders of each of the fasteners and contacting the elastic element with third shoulders of each of the fasteners. 
     
     
       19. The method as recited in  claim 18  wherein the fasteners are sheet metal rivets. 
     
     
       20. The method as recited in  claim 14  wherein the fixing the first and second cover plates together includes axially preloading the elastic element between surfaces of the fasteners and a surface of the second drive flange.